PWM solar controller refers to the use of the digital output of the microprocessor to control the analog circuit, which is a method of digitally encoding the analog signal level. Controlling analog circuits digitally can greatly reduce the cost and power consumption of the system. A PWM controller is included in many microcontrollers.

The basic principle of PWM solar charge controller: When the narrow pulses with the same impulse and different shapes are applied to the link with inertia, the effect is the same. The PWM solar control principle is to divide the waveform into 6 equal parts, which can be replaced by 6 square waves equivalently. There are many classification methods of pulse width modulation, such as unipolar and bipolar, synchronous and asynchronous, rectangular wave modulation and sine wave modulation.
The characteristic of the solar controller is to intelligently adjust the working voltage of the solar power panel, so that the solar panel always works at the maximum power point of the V-A characteristic curve. The charging mode of the ordinary PWM solar controller has three stages: strong charging, balanced charging, and floating charging.